1. Field of the Invention
The present invention relates to a radio terminal, and more particularly to a folding type radio terminal for performing short-range radio communication with a predetermined communication device.
2. Description of the Related Art
Recently, a non-contact IC card that can be used just by being held to a predetermined reader/writer has been in wide use. This non-contact IC card has been widely used for a prepaid card or the like on a railroad or bus.
Associatively, various technologies that combine such non-contact IC cards with commonly-used portable telephones have been proposed. For example, JP 2001-5920 A discloses a technology of shortening a data communication distance between anon-contact IC card and a reader/writer by disposing a portable telephone therebetween. Each of JP 2004-280193 A, JP 2002-218031 A, and JP 2004-310257 A discloses incorporation of an IC chip constituting a non-contact IC card and an antenna in a portable telephone. JP 2004-280193 A further discloses mounting of a reader/writer for performing short-range radio communication with a non-contact IC card in a portable telephone.
The portable telephone having the non-contact IC card mounted therein has conventionally been configured as shown in FIG. 13. This configuration is disclosed in JP 2004-280193 A. As shown in FIG. 13, a folding type portable telephone 1 is configured by interconnecting: a first case 4 including a key operation unit 2 and a microphone 3; and a second case 7 including a display unit 5 and a receiver 6, via a hinge 8, such that the first case 4 and the second case 7 can be folded. An antenna 9 of a non-contact IC card is mounted on the first case 4 side.
In the conventional portable telephone 1 shown in FIG. 13, in order to use the built-in non-contact IC card, the antenna 9 of the built-in non-contact IC card must be brought close to a reader/writer 10. In this case, normally, a user grips the first case 4 side on which the key operation unit 2 and the microphone 3 are mounted. However, the hand of the user gripping the first case 4 hinders the antenna 9 of the non-contact IC card from being brought sufficiently close to the reader/writer 10, which leads to a problem. Further, as the first case 4 is gripped, the hand shields the antenna 9 creating a problem in that satisfactory antenna characteristics cannot be securely attained. In other words, the conventional portable telephone 1 shown in FIG. 13 has a problem in that sufficient communication quality cannot be securely obtained between the non-contact IC card and the reader/writer 10. To solve the problem, the user is required to perform an extra operation, such as to change the way to grip the portable telephone 1, which has been burdensome work for the user.
JP 2004-135054 A discloses a portable telephone equipped with a short-patch antenna and a horizontal dipole antenna, and a technology of switching between the short-patch antenna and the horizontal dipole antenna according to a use state of the portable telephone. JP 11-882223 A discloses a card-type radio device that uses a linear loop antenna when used as a radio modem, and uses a flat-table loop antenna when used as a pager. However, the technologies disclosed in JP 2004-135054 and JP 11-882223 A do not solve the problems of the radio terminal which includes a short-range radio communication function represented by communication between the non-contact IC card and the reader/writer.